The invention relates to a sealed casing for a fluid filter, including a tubular body having an orifice at one of its ends, a cap to tightly seal the orifice, and locking elements to lock the cap onto the tubular body.
In particular, the present invention relates to an aeronautical system for protecting an oil circuit or a circuit feeding fuel to a gas turbine engine. This circuit may require protection against any external contamination from a variety of contaminating sources in contact with the circuit, for example a storage tank or a pump, that might degrade and produce fluid-contaminating particles.
Sealed systems are known wherein sealing is implemented by assembling a casing and a cap with the use of screws and self-locking threads in the casing.
Such systems, however, require screwing or unscrewing the screws during maintenance operations, in particular to change the filter, and therefore entail time-consuming labor. Moreover, repetition of cap assembly or disassembly over time degrades the fastening of the self-locking threads so that the casing may need to be replaced.
The objective of the present invention is to present a sealed casing with a simpler cap assembly or disassembly and easier filter replacement, thereby reducing the shutdown time of a gas turbine engine when the engine maintenance undergoes procedures.
This objective is attained in the present invention through a clamping arrangement which includes at least one radial arcuate segment or member near or at a distal end of a cap that is arranged to slide into at least one clearance defined by a tubular body. The clamping arrangement further includes at least one locking element defined as an extension mounted in an axially displaceable manner on the cap and radially positioned between the at least one arcuate segment of the cap, each extension being configured to be received in an interstice positioned between the arcuate segments of the orifice and arranged to cooperatively secure the cap to the tubular body.
Due to the clamping arrangement, the cap is easily removed by simple rotation. When there are two male arcuate segments and two clearances in the cap and in the tubular body, the cap only needs to be rotated by a quarter turn in order to be clamped onto the tubular body or be released therefrom.
Advantageously, the extensions are biased towards the tubular body by at least one resilient element toward the locked position.
The extensions are elastically applied against the basic body when the cap is in the locked position such that the cap is prevented from rotating.
Advantageously, the clamping arrangement includes a bail.
The bail is positioned at a proximal end portion of the cap and allows gripping of the cap and thereby facilitates the affixation and rotation of the cap onto the tubular body.
Advantageously, the extensions are firmly joined to a drive handle situated near the bail.
Advantageously, the resilient elements are inserted between the bail and the drive handle.
In this manner, pressing the drive handle against the bail is sufficient to disengage the extensions.
Advantageously, the extensions and the drive handle are positioned on a hoop member concentric with the cap.
The hoop member allows configuring the extensions and the resilient elements on a single, easily manufactured structure.
Advantageously, the casing is furthermore fitted with a drain plug.
The drain plug is configured in such manner that it will prevent the cap from any axial displacement and the hoop member precludes any danger of premature disassembly.
Advantageously, sealing is implemented by an O-ring interposed between the orifice and the cap.
The O-ring may be housed in an annular groove in either the orifice of the basic body or in the cap, depending on the cap entering the orifice or enclosing it.
Other features and advantages of the invention are elucidated in the illustrative but non-limiting description below and in relation to the attached drawings.